Unless otherwise configured, the client libraries use Application Default Credentials to authenticate with Google Cloud Services. While this works for most applications, in some cases you may need to override this default. You can do so by providing the UnifiedCredentialsOption The following example shows how to explicitly load a service account key file:
[](std::string const& keyfile) {
auto is = std::ifstream(keyfile);
is.exceptions(std::ios::badbit); // Minimal error handling in examples
auto contents = std::string(std::istreambuf_iterator<char>(is.rdbuf()), {});
auto options =
google::cloud::Options{}.set<google::cloud::UnifiedCredentialsOption>(
google::cloud::MakeServiceAccountCredentials(contents));
return google::cloud::securesourcemanager_v1::SecureSourceManagerClient(
google::cloud::securesourcemanager_v1::
MakeSecureSourceManagerConnection(options));
}
[[["Easy to understand","easyToUnderstand","thumb-up"],["Solved my problem","solvedMyProblem","thumb-up"],["Other","otherUp","thumb-up"]],[["Missing the information I need","missingTheInformationINeed","thumb-down"],["Too complicated / too many steps","tooComplicatedTooManySteps","thumb-down"],["Out of date","outOfDate","thumb-down"],["Samples / code issue","samplesCodeIssue","thumb-down"],["Other","otherDown","thumb-down"]],["Last updated 2025-08-14 UTC."],[[["\u003cp\u003eThe content provides a list of documentation versions for SecureSourceManager, ranging from version 2.37.0-rc (latest) down to 2.18.0.\u003c/p\u003e\n"],["\u003cp\u003eThe primary topic of the documentation is how to override the default authentication credentials for Google Cloud Services using the \u003ccode\u003eUnifiedCredentialsOption\u003c/code\u003e.\u003c/p\u003e\n"],["\u003cp\u003eThe example demonstrates how to load a service account key file explicitly to override the default Application Default Credentials.\u003c/p\u003e\n"],["\u003cp\u003eFor detailed instructions and security best practices about service account keys, refer to the "Best practices for managing service account keys" guide.\u003c/p\u003e\n"],["\u003cp\u003eFor more information on creating \u003ccode\u003egoogle::cloud::Credentials\u003c/code\u003e objects, refer to the "Authentication Components" documentation.\u003c/p\u003e\n"]]],[],null,[]]